package com.xiao.springcloud.lb;

import org.springframework.cloud.client.ServiceInstance;
import org.springframework.stereotype.Component;

import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * @Author xiaoxiaoping
 * @Date 2020/9/6 16:17
 * @Version 1.0
 */
@Component
public class MyLB implements LoadBalancer {
	
	private AtomicInteger atomicInteger = new AtomicInteger(0);
	
	public final int getAndIncrement(){
		int current;
		int next;
		do{
			current = this.atomicInteger.get();
			next = current >= 2147483647 ? 0 : current + 1;
		}while(!this.atomicInteger.compareAndSet(current,next));
		System.out.println("*****next:"+next);
		return next;
	}
	
	@Override
	public ServiceInstance instance(List<ServiceInstance> serviceInstances) {
		int index = getAndIncrement() % serviceInstances.size();
		return serviceInstances.get(index);
	}
}
